I vaguely remember an English joke about how certain Oxford colleges qualified prospective fellows. They’d invite them to a garden party and serve them a bowl of cherries and see how they disposed of the pits. I forget what the candidates were supposed to do.
In the Team Euro Moberg composite, Team Euro has constructed the composite using 10 of the 18 Moberg series, most of which you’ve heard about: Yamal (Briffa version), Tornetrask, the Yang China composite (with HS from two Thompson ice cores) and the Arabian Sea G. bulloides (showing coldwater upwelling), Taymir tree rings, Chesapeake Mg/Ca, a China stalagmite and two odd bristlecones, Methuselah Walk and Indian Garden – both lower border chronologies, related, if anything to precipitation, and without the 20th century growth spurt of Sheep Mountain, Campito Mountain, Boreal and Uppwer Wright, and finallly the GRIP borehole series.
I’ve accurately emulated the Team Euro Moberg composite as shown below using the coloring of yesterday’s exercise.
Team Euro Moberg composite. Black – archived; red- emulation; blue- discrepancy.
Now Moberg used 18 proxies – so what happened with the 8 "cherry pits"? These included the Sargasso Sea dO18 reconstruction – since this is an actual temperature reconstruction (rather than a measure of coldwater upwelling), to the extent that the inclusion of the proxy is being justified on the basis of representation tropical ocean temperatures, the Sargasso Sea proxy is a more defensible selection. Another one is the Indigirka, Siberia chronology. I’ll post more on this on another occasion, but, in my opinion, this chronology – which is the newest – should absolutely be included in any reconstruction as it is independent and offers an excellent opportunity to test the HS as a hypothesis of temperature history.
So below, I show on the left the Team Euro Moberg composite with 10 Moberg proxies and on the right an identically calculated composite replacing Yamal with Indigirka and Arabian Sea G. bulloides with Sargasso Sea temperature estimates. The medieval-modern relationship is reversed.
By the way, the correlation of the right panel reconstruction (the CA variation of the Moberg composite, if you will) is indistinguishable from the Euro Team Moberg composite in its correlation to the EHT instrumental record (r -0.57; EHT version r – 0.58).